As air pollution is on the rise, an air purification device is preventing more and more importance in aspects of life, medical treatment, and production. Some popular air purification devices on the current market implement purification by using a high-voltage electric field under cooperation with an air filter. Normally, a high-voltage filament and a discharge net are spacingly fixed onto an outer frame, such that the high-voltage filament is not contact with the discharge net. The discharge net is subject to induction through a high voltage to produce an electric field and to implement a biocidal treatment. The outer frame is normally made of fire barrier plastic, but during use, such impurities as dust are easily absorbed onto a fixed point of the high-voltage filament on the outer frame the device operates under a high voltage; after long time use, the impurities such as dust are carbonized, and the plastic on the fixed point portion is carbonized; the carbonized plastic is easily fired, which brings potential safety hazards.